Initial commit

openflexure_microscope/api/app.py

@@ -0,0 +1,175 @@
+#!/usr/bin/env python
+#TODO: Completely rewrite for new version of StreamingCamera
+from pprint import pprint
+from importlib import import_module
+import time, datetime
+
+from flask import Flask, render_template, Response, redirect, request, jsonify, send_file
+#import yaml
+import numpy as np
+
+# Raspberry Pi camera module (requires picamera package)
+#from camera.pi import Camera
+from openflexure_microscope.camera.pi import StreamingCamera
+
+app = Flask(__name__)
+cam = StreamingCamera()
+
+def parse_payload(request):
+    # TODO: Try-except for invalid JSON payloads
+    state = request.get_json()
+    return state
+
+def gen(camera):
+    """Video streaming generator function."""
+    while True:
+        # the obtained frame is a jpeg
+        frame = camera.get_frame()
+
+        yield (b'--frame\r\n'
+               b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')
+
+@app.route('/')
+def index():
+    '''
+    Video streaming home page.
+    '''
+    cam.start_worker()  # Start the stream
+    return render_template('index.html')
+
+@app.route('/stream')
+def stream():
+    '''
+    Video streaming route. Put this in the src attribute of an img tag.
+    '''
+    return Response(gen(cam), mimetype='multipart/x-mixed-replace; boundary=frame')
+
+
+#TODO: Be able to change the image resolution with an option
+@app.route('/capture/', methods=['GET', 'POST', 'PUT'])
+def capture():
+    '''
+    POST/PUT: Capture a single image
+    GET: Return capture status, or download latest capture
+
+    Eg. curl http://192.168.1.140:5000/capture/ -H "Content-Type: application/json" -d '{"store":true}' -X POST
+    '''
+    if request.method == 'POST' or request.method == 'PUT':
+        state = parse_payload(request)
+        print(state)
+
+        # Handle filename argument
+        if 'filename' in state:
+            filename = state['filename']
+        else:
+            filename = None
+        
+        if 'write_to_file' in state:
+            write_to_file = bool(state['write_to_file'])
+        else:
+            write_to_file = False
+
+        if 'use_video_port' in state:
+            use_video_port = bool(state['use_video_port'])
+        else:
+            use_video_port = False
+        
+        if 'resize' in state:
+            resize_h = int(state['resize'])
+            resize_w = int(resize_h*(4/3))
+            resize = (resize_w, resize_h)
+        else:
+            resize = None
+
+        response = cam.capture(
+            write_to_file=write_to_file, 
+            use_video_port=use_video_port,
+            filename=filename,
+            resize=resize)
+
+        return str(response) + "\n"
+
+    else:  # If GET request
+
+        download = request.args.get('download')
+
+        state = cam.state
+        
+        if (download == 'true' or download == 'True' or download =='1') and cam.image is not None:
+            return send_file(cam.image.data, mimetype='image/jpeg')
+        else:
+            return jsonify(state)
+
+@app.route('/record/', methods=['GET', 'POST', 'PUT'])
+def record():
+    '''
+    POST/PUT: Start or stop a video recording
+    GET: Return recording status, or download latest recording
+
+    Eg. 
+    curl http://192.168.1.140:5000/record/ -H "Content-Type: application/json" -d '{"status":true}' -X POST
+    curl http://192.168.1.140:5000/record/ -H "Content-Type: application/json" -d '{"status":false}' -X POST
+    '''
+    if request.method == 'POST' or request.method == 'PUT':
+        state = request.get_json()
+        print(state)
+
+        # Handle filename argument
+        if 'filename' in state:
+            filename = state['filename']
+        else:
+            filename = None
+
+        # Handle status argument
+        if 'status' in state:
+            status = bool(state['status'])
+
+        # synchronise the arduino_time
+        if status == True:
+            response = cam.start_recording(filename=filename)
+            return str(response)
+
+        elif status == False:
+            response = cam.stop_recording()
+            return str(response)
+    
+    else:
+        download = request.args.get('download')
+
+        state = cam.state
+        
+        if (download == 'true' or download == 'True' or download =='1') and cam.state_record['recent'] is not None:
+            return send_file(cam.state_record['recent'],
+                mimetype='video/H264',
+                as_attachment=True)
+        else:
+            return jsonify(state)
+
+@app.route('/preview/', methods=['GET', 'POST', 'PUT'])
+def preview():
+    '''
+    POST/PUT: Start or stop the direct-to-GPU camera preview on the Pi
+    GET: Return preview status
+    '''
+    if request.method == 'POST' or request.method == 'PUT':
+        state = request.get_json()
+        print(state)
+
+        if 'status' in state:
+            status = bool(state['status'])
+
+        if status == False:
+            response = cam.stop_preview()
+        else:
+            response = cam.start_preview()
+
+        return str(response)
+    
+    else:
+        # Get args passed via URL (not useful here. Just for reference.)
+        state = cam.state
+        return jsonify(state)
+
+
+if __name__ == '__main__':
+    app.run(host='0.0.0.0', threaded=True, debug=True, use_reloader=False)

openflexure_microscope/api/templates/index.html

@@ -0,0 +1,9 @@
+<html>
+  <head>
+    <title>Video Streaming Demonstration</title>
+  </head>
+  <body>
+    <h1>Video Streaming Demonstration</h1>
+    <img src="{{ url_for('stream') }}">
+  </body>
+</html>